This invention relates generally to the field of wind turbines, and more specifically to localized sensing and actuation systems to reduce the effect of angle of attack deviation (from the planned/controlled value) on power and loads in turbulent winds.
Wind turbines are increasingly gaining importance in the area of renewable sources of energy generation. In recent times, wind turbine technology has been applied to large-scale power generation applications. Maximizing wind turbine performance while minimizing system loads in given wind conditions is one of the many challenges that exist in harnessing wind energy. Non-limiting examples of improved wind turbine performance parameters, which lead to minimized cost of energy, include maximized aerodynamic efficiency, maximized energy output, minimized wind turbine system loads, minimized noise, and combinations thereof. Examples of wind turbine system loads include extreme loads (operational and parked/idling) and fatigue loads.
Reducing the difference between entitlement and actual power capture is one of the main objectives of the control problem for variable speed wind turbines. Strongly coupled with this problem is the reduction of structural loads on the turbine components. Modern wind turbines include very long blades; and this large area of the rotor experiences large wind variations, both in turbulence intensity, as well as shear. Wind turbine blades are generally designed for constant tip speeds, without taking into consideration the nonlinear variations of wind due to turbulence and shear. Employing local actuators that can vary the blade aerodynamics via flow control, to reduce the impact of the wind variation along the blade, also reduces the power loss and loading on the blade. Wind induced loading on the rotor is also reduced at the same time.
In view of the foregoing, it would be beneficial and advantageous to provide a technique for detecting local instantaneous blade loading that can be used to provide information about the actual angle of attack such that localized actuation can be applied to alter the aerodynamics of the blade(s) to compensate for existent angle of attack mismatch in order to reduce its effect on the power capture and load imbalance seen by the turbine components (rotor, drive train, tower).